Sulfonic acid derivative compounds as photoacid generators in resist applications

ABSTRACT

Novel photoacid generator compounds are provided. Photoresist compositions that include the novel photoacid generator compounds are also provided. The invention further provides methods of making and using the photoacid generator compounds and photoresist compositions disclosed herein. The compounds and compositions are useful as photoactive components in chemically amplified resist compositions for various microfabrication applications.

TECHNICAL FIELD

The invention relates to new photoacid generator compounds (“PAGs”) andphotoresist compositions that comprise such PAG compounds. Inparticular, the PAG compounds of the invention have excellent solubilityin organic solvents and exhibit higher sensitivity and betterperformance in a photolithographic process than conventional PAGcompounds.

BACKGROUND

Photoresists are photosensitive films for transfer of images to asubstrate. They form negative or positive images. After coating aphotoresist on a substrate, the coating is exposed through a patternedphotomask to a source of activating energy, such as ultraviolet light,to form a latent image in the photoresist coating. The photomask hasareas opaque and transparent to activating radiation that define animage desired to be transferred to the underlying substrate.

Chemical amplification-type photoresists have proven to be useful inachieving high sensitivity in processes for forming ultrafine patternsin the manufacture of semiconductors. These photoresists are prepared byblending a PAG with a polymer matrix having acid labile structures.According to the reaction mechanism of such a photoresist, the photoacidgenerator generates acid when it is irradiated by the light source, andthe main chain or branched chain of the polymer matrix in the exposed orirradiated portion reacts in a so called “post exposure bake” (PEB) withthe generated acid and is decomposed or cross-linked, so that thepolarity of the polymer is altered. This alteration of polarity resultsin a solubility difference in the developing solution between theirradiated exposed area and the unexposed area, thereby forming apositive or negative image of a mask on the substrate. Acid diffusion isimportant not only to increase photoresist sensitivity and throughput,but also to limit line edge roughness due to shot noise statistics.

In a chemically amplified photoresist, the solubility-switchingchemistry necessary for imaging is not caused directly by the exposure;rather exposure generates a stable catalytic species that promotessolubility-switching chemical reactions during the subsequent PEB step.The term “chemical amplification” arises from the fact that eachphotochemically-generated catalyst molecule can promote manysolubility-switching reaction events. The apparent quantum efficiency ofthe switching reaction is the quantum efficiency of catalyst generationmultiplied by the average catalytic chain length. The original exposuredose is “amplified” by the subsequent chain of chemical reaction events.The catalytic chain length for a catalyst can be very long (up toseveral hundred reaction events) giving dramatic exposure amplification.

Chemical amplification is advantageous in that it can greatly improveresist sensitivity, but it is not without potential drawbacks. Forinstance as a catalyst molecule moves around to the several hundredreactions sites, nothing necessarily limits it to the region that wasexposed to the imaging radiation. There is a potential trade-off betweenresist sensitivity and imaging fidelity. For example, the amplifiedphotoresist is exposed through a photomask, generating acid catalyst inthe exposed regions. The latent acid image generated in the first stepis converted into an image of soluble and insoluble regions by raisingthe temperature of the wafer in the PEB, which allows chemical reactionsto occur. Some acid migrates out of the originally exposed regioncausing “critical dimension bias” problems. After baking, the image isdeveloped with a solvent. The developed feature width may be larger thanthe nominal mask dimension as the result of acid diffusion from exposedinto the unexposed regions. For much of the history of amplified resiststhis trade-off was of little concern as the catalyst diffusion distanceswere insignificant relative to the printed feature size, but as featuresizes have decreased, the diffusion distances have remained roughly thesame and catalyst diffusion has emerged as a significant concern.

In order to generate enough acid which would change the solubility ofthe polymer, a certain exposure time is required. For a known PAGmolecule like N-Hydroxynaphthalimide triflate (“NIT”), this exposuretime is rather long (due to its low absorption at 365 nm or longer).Increasing the concentration of such PAGs, however, will not result infaster exposure times because the solubility of the PAG is the limitingfactor. Another possibility is to add sensitizers which absorb the lightand transfer energy to the PAG which would then liberate the acid. Suchsensitizers, however, must be used in rather high concentrations inorder to be able to transfer the energy to a PAG in close proximity. Atsuch high concentrations, sensitizers often have an absorption which istoo high and has negative effects on the shape of the resist profileafter development.

Accordingly, there is a need in the art for PAGs that exhibit better asolubility, which means that more active molecules are imparted into theformulation, wherein a photoresist composition comprising thesecompounds has a high sensitivity towards electromagnetic radiation, inparticular towards electromagnetic radiation with a wavelength of 200 to500 nm, and—at the same time—allows the production of a patternedstructure with a higher resolution, compared to the photoresistcompositions known from the prior art.

SUMMARY

The invention satisfies this need by providing sulfonic acid derivativecompound represented by either Formula (I) or Formula (II):

wherein R ad R⁰ are as defined herein.

In some embodiments, the invention also provides resist compositionscomprising imaging-effective amounts of one or more PAG according to theinvention and a resin.

In other embodiments, the invention provides methods for forming reliefimages of the photoresists of the invention, including methods forforming highly resolved patterned photoresist images (e.g., a patternedline having essentially vertical sidewalls) of sub-quarter microndimensions or less, such as sub-0.2 or sub-0.1 micron dimensions.

The invention further provides articles of manufacture comprisingsubstrates such as a microelectronic wafer or a flat panel displaysubstrate having coated thereon the photoresists and relief images ofthe invention. Other aspects of the invention are disclosed infra.

BRIEF DESCRIPTION OF DRAWINGS

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawings. It is emphasizedthat, according to common practice, the various features of the drawingsare not to scale. On the contrary, the dimensions of the variousfeatures are arbitrarily expanded or reduced for clarity. Included inthe drawings are the following figures:

FIG. 1 is a UV-Vis spectra of compound T3 upon irradiating with a UVlamp at 365 nm, showing the decrease of the intensity with the increaseof exposure dose of energy (mJ/cm²);

FIG. 2 is a plot of the natural log of the changes in absorbance withexposure dose of energy from the spectra of FIG. 1 to give thephotoreaction constant of T3;

FIG. 3 is a micrograph of patterned structures with variousline-and-space (L/S) sizes (5, 6, 7, 8, 9, and 10 um), wherein T2, acompound of the invention, was employed as the PAG compound; and

FIG. 4 is a UV-Vis spectra of compounds NIT, T1, T2 and T5 in ACN(0.001% w/v).

DETAILED DESCRIPTION Definitions

Unless otherwise stated, the following terms used in this Application,including the specification and claims, have the definitions givenbelow. It must be noted that, as used in the specification and theappended claims, the singular forms “a,” “an,” and “the” include pluralreferents unless the context clearly dictates otherwise.

All numerical designations, such as, weight, pH, temperature, time,concentration, and molecular weight, including ranges, areapproximations which are varied by 10%. It is to be understood, althoughnot always explicitly stated, that all numerical designations arepreceded by the term “about.” It also is to be understood, although notalways explicitly stated, that the reagents described herein are merelyexemplary and that equivalents of such are known in the art.

In reference to the present disclosure, the technical and scientificterms used in the descriptions herein will have the meanings commonlyunderstood by one of ordinary skill in the art, unless specificallydefined otherwise. Accordingly, the following terms are intended to havethe following meanings.

As used herein, the term “moiety” refers to a specific segment orfunctional group of a molecule. Chemical moieties are often recognizedchemical entities embedded in or appended to a molecule.

As used herein the term “aliphatic” encompasses the terms alkyl,alkenyl, alkynyl, each of which being optionally substituted as setforth below.

As used herein, an “alkyl” group refers to a saturated aliphatichydrocarbon group containing from 1-20 (e.g., 2-18, 3-18, 1-8, 1-6, 1-4,or 1-3) carbon atoms. An alkyl group can be straight, branched, cyclicor any combination thereof. Examples of alkyl groups include, but arenot limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,sec-butyl, tert-butyl, n-pentyl, n-heptyl, or 2-ethylhexyl. An alkylgroup can be substituted (i.e., optionally substituted) with one or moresubstituents or can be multicyclic as set forth below.

Unless specifically limited otherwise, the term “alkyl,” as well asderivative terms such as “alkoxy” and “thioalkyl,” as used herein,include within their scope, straight chain, branched chain and cyclicmoieties.

As used herein, an “alkenyl” group refers to an aliphatic carbon groupthat contains from 2-20 (e.g., 2-18, 2-8, 2-6, or 2-4) carbon atoms andat least one double bond. Like an alkyl group, an alkenyl group can bestraight, branched or cyclic or any combination thereof. Examples of analkenyl group include, but are not limited to, allyl, isoprenyl,2-butenyl, and 2-hexenyl. An alkenyl group can be optionally substitutedwith one or more substituents as set forth below.

As used herein, an “alkynyl” group refers to an aliphatic carbon groupthat contains from 2-20 (e.g., 2-8, 2-6, or 2-4) carbon atoms and has atleast one triple bond. An alkynyl group can be straight, branched orcyclic or any combination thereof. Examples of an alkynyl group include,but are not limited to, propargyl and butyryl. An alkynyl group can beoptionally substituted with one or more substituents as set forth below.

A “halogen” is an atom of the 17th Group of the period table, whichincludes fluorine, chlorine, bromine and iodine.

As used herein, an “aryl” group used alone or as part of a larger moietyas in “aralkyl,” “aralkoxy,” or “aryloxyalkyl” refers to monocyclic(e.g., phenyl); bicyclic (e.g., indenyl, naphthalenyl,tetrahydronaphthyl, tetrahydroindenyl); and tricyclic (e.g., fluorenyltetrahydrofluorenyl, or tetrahydroanthracenyl, anthracenyl) ring systemsin which the monocyclic ring system is aromatic or at least one of therings in a bicyclic or tricyclic ring system is aromatic. The bicyclicand tricyclic groups include benzofused 2-3 membered carbocyclic rings.For example, a benzofused group includes phenyl fused with two or moreC₄₋₈ carbocyclic moieties. An aryl is optionally substituted with one ormore substituents as set forth below.

As used herein, an “aralkyl” or “arylalkyl” group refers to an alkylgroup (e.g., a C₁₋₄ alkyl group) that is substituted with an aryl group.Both “alkyl” and “aryl” have been defined above. An example of anaralkyl group is benzyl. An aralkyl is optionally substituted with oneor more substituents as set forth below.

As used herein, a “cycloalkyl” group refers to a saturated carbocyclicmono- or bicyclic (fused or bridged) ring of 3-10 (e.g., 5-10) carbonatoms. Examples of cycloalkyl groups include cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, cubyl,octahydro-indenyl, decahydro-naphthyl, bicyclo[3.2.1]octyl,bicyclo[2.2.2]octyl, bicyclo[3.3.1]nonyl, bicyclo[3.3.2]decyl,bicyclo[2.2.2]octyl, adamantyl, azacycloalkyl, or((aminocarbonyl)cycloalkyl)cycloalkyl.

As used herein, the term “heteroaryl” group refers to a monocyclic,bicyclic, or tricyclic ring system having 4 to 18 ring atoms wherein oneor more of the ring atoms is a heteroatom (e.g., N, O, S, orcombinations thereof) and in which the monocyclic ring system isaromatic or at least one of the rings in the bicyclic or tricyclic ringsystems is aromatic. A heteroaryl group includes a benzofused ringsystem having 2 to 3 rings. For example, a benzofused group includesbenzo fused with one or two 4 to 8 membered heterocycloaliphaticmoieties (e.g., indolizyl, indolyl, isoindolyl, 3H-indolyl, indolinyl,benzo[b]furyl, benzo[b]thiophenyl, quinolinyl, or isoquinolinyl). Someexamples of heteroaryl are azetidinyl, pyridyl, 1H-indazolyl, furyl,pyrrolyl, thienyl, thiazolyl, oxazolyl, imidazolyl, tetrazolyl,benzofuryl, isoquinolinyl, benzthiazolyl, xanthene, thioxanthene,phenothiazine, dihydroindole, benzo[1,3]dioxole, benzo[b]furyl,benzo[b]thiophenyl, indazolyl, benzimidazolyl, benzthiazolyl, puryl,cinnolyl, quinolyl, quinazolyl, cinnolyl, phthalazyl, quinazolyl,quinoxalyl, isoquinolyl, 4H-quinolizyl, benzo-1,2,5-thiadiazolyl, or1,8-naphthyridyl.

Without limitation, monocyclic heteroaryls include furyl, thiophenyl,2H-pyrrolyl, pyrrolyl, oxazolyl, thazolyl, imidazolyl, pyrazolyl,isoxazolyl, isothiazolyl, 1,3,4-thiadiazolyl, 2H-pyranyl, 4-H-pranyl,pyridyl, pyridazyl, pyrimidyl, pyrazolyl, pyrazyl, or 1,3,5-triazyl.Monocyclic heteroaryls are numbered according to standard chemicalnomenclature.

Without limitation, bicyclic heteroaryls include indolizyl, indolyl,isoindolyl, 3H-indolyl, indolinyl, benzo[b]furyl, benzo[b]thiophenyl,quinolinyl, isoquinolinyl, indolizyl, isoindolyl, indolyl,benzo[b]furyl, bexo[b]thiophenyl, indazolyl, benzimidazyl,benzthiazolyl, purinyl, 4H-quinolizyl, quinolyl, isoquinolyl, cinnolyl,phthalazyl, quinazolyl, quinoxalyl, 1,8-naphthyridyl, or pteridyl.Bicyclic heteroaryls are numbered according to standard chemicalnomenclature.

A heteroaryl is optionally substituted with one or more substituents asis set forth below.

A “heteroarylalkyl” group, as used herein, refers to an alkyl group(e.g., a C₁₋₄ alkyl group) that is substituted with a heteroaryl group.Both “alkyl” and “heteroaryl” have been defined above. A heteroarylalkylis optionally substituted with one or more substituents as is set forthbelow.

As used herein, an “acyl” group refers to a formyl group or R^(X)—C(O)—(such as -alkyl-C(O)—, also referred to as “alkylcarbonyl”) where“alkyl” have been defined previously.

As used herein, the term “acyloxy” includes straight-chain acyloxy,branched-chain acyloxy, cycloacyloxy, cyclic acyloxy,heteroatom-unsubstituted acyloxy, heteroatom-substituted acyloxy,heteroatom-unsubstituted C_(n)-acyloxy, heteroatom-substitutedC_(n)-acyloxy, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy,aryloxycarbonyloxy, and carboxylate groups.

As used herein, an “alkoxy” group refers to an alkyl-O— group where“alkyl” has been defined previously.

As used herein, a “carboxy” group refers to —COOH, —COOR^(X), —OC(O)H,—OC(O)R^(X) when used as a terminal group; or —OC(O)— or —C(O)O— whenused as an internal group.

As used herein, “Alkoxycarbonyl” means —COOR where R is alkyl as definedabove, e.g., methoxycarbonyl, ethoxycarbonyl, and the like.

As used herein, a “sulfonyl” group refers to —S(O)₂—R^(X) when usedterminally and —S(O)₂— when used internally.

The term “alkylthio” includes straight-chain alkylthio, branched-chainalkylthio, cycloalkylthio, cyclic alkylthio, heteroatom-unsubstitutedalkylthio, heteroatom-substituted alkylthio, heteroatom-unsubstitutedC_(n)-alkylthio, and heteroatom-substituted C_(n)-alkylthio. In certainembodiments, lower alkylthios are contemplated.

As used herein, the term “amine” or “amino” includes compounds where anitrogen atom is covalently bonded to at least one carbon or heteroatom.The term “amine” or “amino” also includes —NH₂ and also includessubstituted moieties. The term includes “alkyl amino” which comprisesgroups and compounds wherein the nitrogen is bound to at least oneadditional alkyl group. The term includes “dialkyl amino” groups whereinthe nitrogen atom is bound to at least two additional independentlyselected alkyl groups. The term includes “arylamino” and “diarylamino”groups wherein the nitrogen is bound to at least one or twoindependently selected aryl groups, respectively.

The term “haloalkyl” refers to alkyl groups substituted with from one upto the maximum possible number of halogen atoms. The terms “haloalkoxy”and “halothioalkyl” refer to alkoxy and thioalkyl groups substitutedwith from one up to five halogen atoms.

The phrase “optionally substituted” is used interchangeably with thephrase “substituted or unsubstituted.” As described herein, compounds ofthe invention can optionally be substituted with one or moresubstituents, such as are illustrated generally above, or as exemplifiedby particular classes, subclasses, and species of the invention. Asdescribed herein any of the above moieties or those introduced below canbe optionally substituted with one or more substituents describedherein. Each substituent of a specific group is further optionallysubstituted with one to three of halo, cyano, oxoalkoxy, hydroxy, amino,nitro, aryl, haloalkyl, and alkyl. For instance, an alkyl group can besubstituted with alkylsulfanyl and the alkylsulfanyl can be optionallysubstituted with one to three of halo, cyano, oxoalkoxy, hydroxy, amino,nitro, aryl, haloalkyl, and alkyl.

In general, the term “substituted,” whether preceded by the term“optionally” or not, refers to the replacement of hydrogen radicals in agiven structure with the radical of a specified substituent. Specificsubstituents are described above in the definitions and below in thedescription of compounds and examples thereof. Unless otherwiseindicated, an optionally substituted group can have a substituent ateach substitutable position of the group, and when more than oneposition in any given structure can be substituted with more than onesubstituent selected from a specified group, the substituent can beeither the same or different at every position. A ring substituent, suchas a heterocycloalkyl, can be bound to another ring, such as acycloalkyl, to form a spiro-bicyclic ring system, e.g., both rings shareone common atom. As one of ordinary skill in the art will recognize,combinations of substituents envisioned by this invention are thosecombinations that result in the formation of stable or chemicallyfeasible compounds.

Modifications or derivatives of the compounds disclosed throughout thisspecification are contemplated as being useful with the methods andcompositions of the invention. Derivatives may be prepared and theproperties of such derivatives may be assayed for their desiredproperties by any method known to those of skill in the art. In certainaspects, “derivative” refers to a chemically modified compound thatstill retains the desired effects of the compound prior to the chemicalmodification.

Sulfonic Acid Derivate Photoacid Generator Compounds

The sulfonic acid derivative compounds according to the invention can beused as photoacid generators as will be explained in more detail below.Surprisingly, it has been discovered that PAG compounds of the inventionare characterized by excellent solubility and photoreactivity towardselectromagnetic radiation, in particular towards electromagneticradiation with a wavelength in the range from 150 to 500 nm, preferablyin the range from 300 to 450 nm, more preferably in the range from 350to 440 nm, more preferably at wavelengths of 365 nm (i-line), 405(h-line) and 436 nm (g-line).

The sulfonic acid derivative compounds according to the invention areN-hydroxynaphthalimide sulfonate derivatives represented by eitherFormula (I) or Formula (II):

wherein R⁰ is selected from the group consisting of

-   -   a hydrogen atom,    -   an aliphatic group having a carbon number of from 1 to 18 in        which one or more hydrogen atoms may be substituted by a halogen        atom,    -   an aliphatic group having a carbon number of from 2 to 18 which        comprises at least one moiety selected from the group consisting        of —O—, —S—, —C(═O)—, —C(═O)—O—, —C(═O)—S—, —O—C(═O)—O—,        —C(═O)—NH—, —O—C(═O)—NH—, —C(═O)—NR_(a)—, —O—C(═O)—NR_(a)—, and        —C(═O)—NR_(a)R_(b), wherein R_(a) and R_(b) are each        independently an aliphatic group with a carbon number of from 1        to 10, which may be the same or different and may be connected        to form an alicyclic group, and wherein the aliphatic group        optionally comprises at least one halogen atom; and

R is selected from the group consisting of

-   -   —CH₃, —CH₂F, —CHF₂, or —CF₃,    -   an aliphatic group having a carbon number of from 2 to 18, which        may be substituted by one or more halogen atom(s),    -   an aliphatic group having a carbon number of from 2 to 18 which        comprises at least one moiety selected from the group consisting        of —O—, —S—, —C(═O)—, —C(═O)—O—, —C(═O)—S—, —O—C(═O)—O—,        —C(═O)—NH—, —O—C(═O)—NH—, —C(═O)—NR_(a)—, —O—C(═O)—NR_(a)—, and        —C(═O)—NR_(a)R_(b), wherein R_(a) and R_(b) are as defined        above, wherein the aliphatic group optionally comprises at least        one halogen atom,    -   an aryl or heteroaryl group having a carbon number of from 4 to        18 in which one or more hydrogen atoms may be substituted by a        halogen atom, an aliphatic, an haloalkyl, an alkoxy, a        haloalkoxy, an alkylthio, a bisalkylamino, an acyloxy, an        acylthio, an acylamino, an alkoxycarbonyl, an alkylsulfonyl, an        alkylsulfinyl, an alicyclic, a heterocyclic, an aryl, an        alkylaryl, a cyano, or a nitro group, and    -   an arylalkyl or heteroarylalkyl group having a carbon number of        from 4 to 18 in which one or more hydrogen atoms in the aryl or        heteroaryl group may be substituted by a halogen atom, an        aliphatic, a haloalkyl, an alkoxy, a haloalkoxy, an alkylthio, a        bisalkylamino, an acyloxy, an acylthio, an acylamino, an        alkoxycarbonyl, an alkylsulfonyl, an alkylsulfinyl, an        alicyclic, a heterocyclic, an aryl, an alkylaryl, a cyano, or a        nitro group,

with the proviso that, if R is —CF₃, then R⁰ is selected from the groupconsisting of

-   -   a hydrogen atom;    -   an aliphatic group having a carbon number of from 2 to 18 which        comprises at least one moiety selected from the group consisting        of —O—, —S—, —C(═O)—, —C(═O)—O—, —C(═O)—S—, —O—C(═O)—O—,        —C(═O)—NH—, —O—C(═O)—NH—, —C(═O)—NR_(a)—, —O—C(═O)—NR_(a)—, and        —C(═O)—NR_(a)R_(b), wherein R_(a) and R_(b) are as defined        above, wherein the aliphatic group optionally comprises at least        one halogen atom;    -   —CH₂CH(CH₃)₂, —CH₂CH═CHCH₃, or —CH₂CH₂CH═CH₂,    -   a group represented by the Formula (A):

wherein R¹¹ is selected from the group consisting of an aliphatic grouphaving a carbon number of from 4 to 18,

-   -   cyclopropenyl, and    -   a group represented by the Formula (B):

wherein R²¹ is selected from the group consisting of a hydrogen atom oran alkyl group having a carbon number of from 1 to 10; and n is equal to1 to 5.

In some embodiments, R⁰ in Formulas (I) and (II) is an aliphatic grouphaving a carbon number of from 1 to 18 in which one or more hydrogenatoms may be substituted by a halogen atom. Preferred examples includemethyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl,tert-butyl, n-pentyl, n-hexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl,and n-decyl. In an embodiment, R⁰ in Formulas (I) and (II) is analiphatic group having a carbon number of from 1 to 18 in which one ormore hydrogen atoms may be substituted by a halogen atom and R is analiphatic group having a carbon number of from 1 to 18, which may besubstituted by one or more halogen atom(s). Preferably, R is analiphatic group having a carbon number of from 1 to 6 and, morepreferably, an aliphatic group having a carbon number of from 1 to 4,which is substituted by at least one fluorine atom. Examples of such PAGcompounds include those in Table 1:

TABLE 1

T1 

T3 

T11

In other embodiments, R⁰ in Formulas (I) and (II) is an aliphatic grouphaving a carbon number of from 2 to 18 which comprises at least one—C(═O)—O— moiety. In an embodiment, R⁰ in Formulas (I) and (II) is analiphatic group having a carbon number of from 2 to 18 which comprisesat least one —C(═O)—O— moiety and R is an aliphatic group having acarbon number of from 1 to 18, which may be substituted by one or morehalogen atom(s). Preferably, R is an aliphatic group having a carbonnumber of from 1 to 6 and, more preferably, an aliphatic group having acarbon number of from 1 to 4, which is substituted by at least onefluorine atom. Examples of such PAG compounds include those in Table 2:

TABLE 2

T24

T25

In yet other embodiments, R⁰ in Formulas (I) and (II) is an aliphaticgroup having a carbon number of from 1 to 18 in which one or morehydrogen atoms may be substituted by a halogen atom. In anotherembodiment, R⁰ in Formulas (I) and (II) is an aliphatic group having acarbon number of from 1 to 18 in which one or more hydrogen atoms may besubstituted by a halogen atom and R is an aryl or heteroaryl grouphaving a carbon number of from 4 to 18 in which one or more hydrogenatoms may be substituted by a halogen atom, an aliphatic group, or ahaloalkyl group. Examples of such PAG compounds include those in Table3:

TABLE 3

T36

T37

In the most preferred embodiments of Formulas (I) and (II) according tothe invention, R is —CF₃. In such embodiments the above-recited provisoapplies. Preferred embodiments include compounds where R⁰ is a grouprepresented by the Formula (A): —CH₂—R¹¹ (A), wherein R¹¹ is selectedfrom the group consisting of an aliphatic group having a carbon numberof from 4 to 18. Examples include n-butyl, iso-butyl, sec-butyl,tert-butyl, n-pentyl, n-hexyl, 2-ethylhexyl, n-heptyl, n-octyl, n-nonyl,and n-decyl. Examples of such preferred PAG compounds include those inTable 4:

TABLE 4

T2 

T6 

T7 

T10

T13

In other preferred embodiments where R is —CF₃ in Formulas (I) and (II),R⁰ is an aliphatic group having a carbon number of from 2 to 18 whichcomprises at least one —C(═O)—O— or —O—C(═O)—O— moiety, wherein thealiphatic group optionally comprises at least one halogen atom. Examplesof such preferred PAG compounds include those in Table 5:

TABLE 5

T4 

T5 

T8 

T9 

T12

T14

T16

T17

T18

T19

T20

T22

T23

T32

T33

T34

T35

In yet other preferred embodiments where R is —CF₃ in Formulas (I) and(II), R⁰ is an aliphatic group having a carbon number of from 2 to 18which comprises at least one —O—, —S—, or —C(═O)— moiety, wherein thealiphatic group optionally comprises at least one halogen atom. Examplesof such preferred PAG compounds include those in Table 6:

TABLE 6

T15

T21

T29

In yet other preferred embodiments where R is —CF₃ in Formulas (I) and(II), R⁰ is an aliphatic group having a carbon number of from 2 to 18which comprises at least one —C(═O)—S—, —C(═O)—NH—, —O—C(═O)—NH—,—C(═O)—NR_(a)—, —O—C(═O)—NR_(a)—, or —C(═O)—NR_(a)R_(b) moiety, whereinR_(a) and R_(b) are as defined above, and wherein the aliphatic groupoptionally comprises at least one halogen atom. Examples of suchpreferred PAG compounds include those in Table 7:

TABLE 7

T26

T30

T31

T28

In another preferred embodiment where R is —CF₃ in Formulas (I) and(II), R⁰ is a group represented by the Formula (B):

wherein R²¹ is selected from the group consisting of a hydrogen atom oran alkyl group having a carbon number of from 1 to 10; and n is equal to1 to 5. An example of such PAG compound is compound T27

In other embodiments of the invention, both R and R⁰ in Formulas (I) and(II) are an aliphatic group having a carbon number of from 1 to 18.Examples of such PAG compounds include compounds T38 and T40:

In other embodiments of the invention, R in Formulas (I) and (II) is analiphatic group having a carbon number of from 2 to 18 which comprisesat least one —C(═O)— moiety and R⁰ in Formulas (I) and (II) is analiphatic group having a carbon number of from 1 to 18. Examples of suchPAG compounds include compound T39:

PAGs according to the invention impart a high degree of efficiency tothe photolithography process and leads to enhanced contrast andresolution between exposed and unexposed regions of the resistcomposition. The amount of PAG and the energy supplied by the UVirradiation are chosen such that they are sufficient to allow thedesired polycondensation.

PAGs of the invention may be suitably used in positive-acting ornegative-acting chemically amplified photoresists, i.e., negative-actingresist compositions which undergo a photoacid-promoted cross-linkingreaction to render exposed regions of a coating layer of the resist lessdeveloper soluble than unexposed regions, and positive-acting resistcompositions which undergo a photoacid-promoted deprotection reaction ofacid labile groups of one or more composition components to renderexposed regions of a coating layer of the resist more soluble in anaqueous developer than unexposed regions.

Preferred imaging wavelengths for photoresists of the invention includesub-300 nm wavelengths, e.g., 248 nm, and sub-200 nm wavelengths, e.g.,193 nm and EUV, more preferably in the range from 200 to 500 nm,preferably in the range from 300 to 450 nm, even more preferably in therange from 350 to 440 nm, most preferably at wavelengths of 365 nm(i-line), 405 (h-line) and 436 nm (g-line).

Preparation of Compounds of Formulas (I) and (II) (Further Details inthe Examples)

There is no particular limitation for the method for producing theN-hydroxynaphthalimide sulfonate derivative compounds of the invention,and any known synthesis can be used to make the compounds of Formulas(I) and (II). There is no particular limitation for the method forproducing the N-hydroxynaphthalimide sulfonate derivative compounds, andany well-known approach can be used for the synthesis of thesecompounds. Two typical routes that we adopted to synthesize triflatecompounds are illustrated in Scheme 1. Compounds with a triple-bondsubstituent at 3 position can be similarly synthesized by starting from3-bromo anhydride. The starting anhydrides (4-bromo-1,8-naphthalicanhydride and 3-bromo-1,8-naphthalic anhydride) are commerciallyavailable.

As shown in Scheme 1, Sonagashira coupling between4-bromo-1,8-naphthalic anhydride and a terminal alkyne affordsnaphthalic anhydrides with a triple-bond substituent. These anhydridesare converted to the final N-hydroxynaphthalimide sulfonate derivativesvia two different approaches. The first approach involves an one-potreaction using 2.2 equivalents of triflic anhydride. The second approachallows for the isolation of N-hydroxyl imide intermediates and only 1.2equivalent of triflic anhydride is required.

Photoresist Compositions

Photoresist compositions of the invention comprise (i) at least onephotoacid generator selected from Formula (I) and (II); (ii) at leastone photoresist polymer or copolymer which may be base soluble orinsoluble; (iii) an organic solvent; and, optionally, (iv) an additive.

Photoresist compositions according to the invention comprising thephotoacid generators of Formulas (I) and (II) are suitable for use as aphotoresist in a variety of applications, in particular for theproduction of electronic devices, including flat panel display (in thiscase the photoresist can be coated glass substrate or a layer of indiumtin oxide) and a semiconductor device (in this case the photoresist canbe coated onto a silicon wafer substrate). Various exposure radiationscan be used, including an exposure with electromagnetic radiation havinga wavelength of 200 to 500 nm, preferably in the range from 300 to 450nm, more preferably in the range from 350 to 440 nm, even morepreferably at 365 nm (i-line), 436 nm (g-line) or 405 nm (h-line),wherein an electromagnetic radiation with a wavelength of 365 nm isparticularly preferred.

The photoresist compositions according to the invention comprise ascomponent (ii) one or more photoresist polymers or copolymers, which maybe soluble or insoluble in a developer solution. The photoresistcompositions according to the invention may be for positive tone ornegative tone composition. In the case of a positive tone compositionthe solubility of component (ii) is increased upon reaction with theacid released from the compound according to the invention. In thiscase, photoresist polymers or copolymers with acid labile groups areused as component (ii) which are insoluble in aqueous base solution, butwhich in the presence of the acid are catalytically de-protected suchthat they become soluble in solution. In the case of a negative tonecomposition, the solubility of component (ii) is decreased upon reactionwith the acid released from the compound according to the invention. Inthis case, photoresist polymers or copolymers are used as component (ii)which are soluble in the developer solution, but are cross-linked in thepresence of the acid such that they become insoluble in an aqueous basesolution. Thus, photoresist polymers or copolymers are capable of beingimparted with an altered solubility in a developer solution in thepresence of an acid. Preferably the developer solution is an aqueoussolution, more preferably it is an aqueous base solution.

Examples of photoresist polymers that may be used as component (ii) in apositive tone composition include without limitation, aromatic polymers,such as homopolymers or copolymers of hydroxystyrene protected with anacid labile group; acrylates, such as for example, poly(meth)acrylateswith at least one unit containing a pendant alicyclic group, and withthe acid labile group being pendant from the polymer backbone and/orfrom the aclicyclic group, cycloolefin polymers, cycloolefin maleicanhydride copolymers, cycloolefin vinyl ether copolymers, siloxanes;silsesquioxanes, carbosilanes; and oligomers, including polyhedraloligomeric silsesquioxanes, carbohydrates, and other cage compounds. Theforegoing polymers or oligomers are appropriately functionalized withaqueous base soluble groups, acid-labile groups, polar functionalities,and silicon containing groups as needed.

Examples of copolymers that may be used as component (ii) in thepositive tone compositions of the invention include without limitationpoly(p-hydroxystyrene)-methyl adamantyl methacrylate (PHS-MAdMA),poly(p-hydroxystyrene)-2-ethyl-2-adamantyl methacrylate (PHS-EAdMA),poly(p-hydroxystyrene)-2-ethyl-2-cyclopentyl methacrylate (PHS-ECpMA),poly(p-hydroxy-styrene)-2-methyl-2-cyclopentyl methacrylate (PHS-MCpMA)or PHS-EVE.

Preferably, the at least one component (ii) in a positive tonecomposition is a poly(hydroxystyrene)-resin in which at least a part ofthe hydroxy groups is substituted by protective groups. Preferredprotective groups are selected from the group consisting of atert-butoxycarbonyloxy group, a tert-butyloxy group, atert-amyloxycarbonyloxy group and an acetal group. Furthermore suitableas component ii) are all the polymers and copolymers which in paragraphs[0068] to [0114] of EP 1 586 570 A1 are described as “acid-dissociablegroup-containing resin.” The disclosure of EP 1 586 570 A1 with respectto these resins is incorporated herein by reference a forms a part ofthe disclosure of the invention.

Preferred negative tone compositions comprise a mixture of materialsthat will cure, crosslink or harden upon exposure to acid. Preferrednegative acting compositions comprise, as component (ii), a polymerbinder such as a phenolic or non-aromatic polymer, a cross-linkercomponent as an additive (iv) and the photoacid generator componentaccording to the invention as component (i). Suitable polymer bindersand cross-linkers for such negative tone photoresist compositions andthe use thereof have been disclosed in EP-A-0 164 248 and U.S. Pat. No.5,128,232. Preferred phenolic polymers for use as component (ii) includenovolaks and poly(vinylphenol)s. Novolak resins are the thermoplasticcondensation products of a phenol and an aldehyde. Examples of suitablephenols for condensation with an aldehyde, especially formaldehyde, forthe formation of novolak resins include phenol, m-cresol, o-cresol,p-cresol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol and thymol.An acid catalyzed condensation reaction results in the formation of asuitable novolak resin which may vary in molecular weight from about 500to 100,000 Daltons. Polyvinyl phenol resins are thermoplastic polymersthat may be formed by block polymerization, emulsion polymerization orsolution polymerization of the corresponding monomers in the presence ofa cationic catalyst. Vinylphenols useful for the production of polyvinylphenol resins may be prepared, for example, by hydrolysis ofcommercially available coumarin or substituted coumarins, followed bydecarboxylation of the resulting hydroxy cinnamic acids. Usefulvinylphenols may also be prepared by dehydration of the correspondinghydroxy alkyl phenols or by decarboxylation of hydroxy cinnamic acidsresulting from the reaction of substituted or non-substitutedhydroxybenzaldehydes with malonic acid. Preferred polyvinyl phenolresins prepared from such vinylphenols have a molecular weight range offrom about 2,000 to about 60,000 daltons. Preferred cross-linkers foruse as component (iv) include amine-based materials, including melamine,glycolurils, benzoguanamine-based materials and urea-based materials.Melamine-formaldehyde polymers are often particularly suitable. Suchcross-linkers are commercially available, e.g., the melamine polymers,glycoluril polymers, urea-based polymer and benzoguanamine polymers,such as those sold by Cytec under trade names Cymel™ 301, 303, 1170,1171, 1172, 1123 and 1125 and Beetle™ 60, 65 and 80.

As component (iii) the composition according to the invention comprisesat least one organic solvent. The organic solvent may be any solventcapable of dissolving the component (ii) and the component (i) togenerate a uniform solution, and one or more solvents selected fromknown materials used as the solvents for conventional chemicallyamplified resists can be used. Specific examples of the organic solventinclude ketones such as acetone, methyl ethyl ketone, cyclohexanone,methyl isoamyl ketone and 2-heptanone, polyhydric alcohols andderivatives thereof such as ethylene glycol, ethylene glycolmonoacetate, diethylene glycol, diethylene glycol monoacetate, propyleneglycol, propylene glycol monoacetate, dipropylene glycol, or themonomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether ormonophenyl ether of dipropylene glycol monoacetate, cyclic ethers suchas dioxane, and esters such as methyl lactate, ethyl lactate (EL),methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethylpyruvate, methyl methoxypropionate, and ethyl ethoxypropionate. Theseorganic solvents can be used alone, or as a mixed solvent containing twoor more different solvents. Particularly preferred organic solvents(iii) are selected from the group consisting of a ketone, an ether andester.

Furthermore, the composition according to the invention may also,optionally, comprise at least one additive being different fromcomponents (i), (ii) and (iii). For example, other optional additivesinclude actinic and contrast dyes, anti-striation agents, plasticizers,speed enhancers, sensitizers, etc. Such optional additives typicallywill be in minor concentration in a photoresist composition except forfillers and dyes which may be in relatively large concentrations suchas, e.g., in amounts of from 5 to 30 percent by weight of the totalweight of a resist's dry components.

One additive typically employed in photoresist compositions according tothe invention is a basic quencher. The basic quencher is for purposes ofneutralizing acid generated in the surface region of the underlyingphotoresist layer by stray light which reaches what are intended to beunexposed (dark) regions of the photoresist layer. This allows forimprovement in depth of focus in the defocus area and exposure latitudeby controlling unwanted deprotection reaction in the unexposed areas. Asa result, irregularities in the profile, for example, necking andT-topping, in formed resist patterns can be minimized or avoided.

To allow for effective interaction between the basic quencher and theacid generated in the dark areas of the underlying photoresist layer,the basic quencher should be of a non-surfactant-type. That is, thebasic quencher should not be of a type that migrates to the top surfaceof the overcoat layer due, for example, to a low surface free energyrelative to other components of the overcoat composition. In such acase, the basic quencher would not be appreciably at the photoresistlayer interface for interaction with the generated acid to prevent aciddeprotection. The basic quencher should therefore be of a type that ispresent at the overcoat layer/photoresist layer interface, whether beinguniformly dispersed through the overcoat layer or forming a graded orsegregated layer at the interface. Such a segregated layer can beachieved by selection of a basic quencher having a high surface freeenergy relative to other components of the overcoat composition.

Suitable basic quenchers include, for example: linear and cyclic amidesand derivatives thereof such as N,N-bis(2-hydroxyethyl)pivalamide,N,N-Diethylacetamide, N1,N1,N3,N3-tetrabutylmalonamide,1-methylazepan-2-one, 1-allylazepan-2-one and tert-butyl1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylcarbamate; aromatic aminessuch as pyridine, and di-tert-butyl pyridine; aliphatic amines such astriisopropanolamine, n-tert-butyldiethanolamine,tris(2-acetoxy-ethyl)amine,2,2′,2″,2″′-(ethane-1,2-diylbis(azanetriyl))tetraethanol, and2-(dibutylamino)ethanol, 2,2′,2″-nitrilotriethanol; cyclic aliphaticamines such as 1-(tert-butoxycarbonyl)-4-hydroxypiperidine, tert-butyl1-pyrrolidinecarboxylate, tert-butyl 2-ethyl-1H-imidazole-1-carboxylate,di-tert-butyl piperazine-1,4-dicarboxylate and N(2-acetoxy-ethyl)morpholine. Of these basic quenchers,1-(tert-butoxycarbonyl)-4-hydroxypiperidine and triisopropanolamine arepreferred. While the content of the basic quencher will depend, forexample, on the content of the photoacid generator in the underlyingphotoresist layer, it is typically present in an amount of from 0.1 to 5wt %, preferably from 0.5 to 3 wt %, more preferably from 1 to 3 wt %,based on total solids of the overcoat composition.

Another concept is to attach a basic moiety to the PAG molecule. In thiscase the quencher is a part of the PAG and in close proximity to theacid formed upon irradiation. These compounds have a high sensitivitytowards electromagnetic radiation, in particular towards electromagneticradiation with a wavelength in the range of 200 to 500 nm, moreparticularly towards electromagnetic radiation with a wavelength of 365nm (i-line), and—at the same time —allows the production of a patternedstructure with a higher resolution, compared to the photoresistcompositions known from the prior art containing quenchers as additives.Compounds that follow this concept are for example T26, T30, and T31.

The resin binder component of resists of the invention are typicallyused in an amount sufficient to render an exposed coating layer of theresist developable such as with an aqueous alkaline solution. Moreparticularly, a resin binder will suitably comprise 50 to about 90weight percent of total solids of the resist. The photoactive componentshould be present in an amount sufficient to enable generation of alatent image in a coating layer of the resist. More specifically, thephotoactive component will suitably be present in an amount of fromabout 1 to 40 weight percent of total solids of a resist. Typically,lesser amounts of the photoactive component will be suitable forchemically amplified resists.

According to a preferred embodiment, the compositions according to theinvention comprise:

(i) 0.05 to 15 wt. %, preferably 0.1 to 12.5 wt. % and most preferably 1to 10 wt. % of at least one photoacid generator compound of Formula (I)or (II);

(ii) 5 to 50 wt. %, preferably 7.5 to 45 wt. % and most preferably 10 to40 wt. % of at least one photoresist polymer or copolymer which may bebase soluble or insoluble; and

(iv) 0 to 10 wt. %, preferably 0.01 to 7.5 wt. % and most preferably 0.1to 5 wt. % of the further additive, wherein the reminder in thecomposition is the organic solvent (iii).

As in the compounds according to the invention the functional basicgroup serving as a quencher for the acid group that is released uponexposure to electromagnetic radiation is a part of the photoacidgenerator compound, it is not necessary to add a separate basiccomponent as a quencher (as it is necessary in the photoresistcompositions known from the prior art). According to a preferredembodiment of the composition according to the invention thiscomposition preferably comprises less than 5 wt. %, more preferably lessthan 1 wt. %, even more preferably less than 0.1 wt. %, and mostpreferably 0 wt. % of a basic compound being different from components(i) through (iv), such as hydroxides, carboxylates, amines, imines, andamides.

The photoresists of the invention are generally prepared following knownprocedures with the exception that a PAG of the invention is substitutedfor prior photoactive compounds used in the formulation of suchphotoresists. For example, a resist of the invention can be prepared asa coating composition by dissolving the components of the photoresist ina suitable solvent such as, e.g., a glycol ether such as 2-methoxyethylether (diglyme), ethylene glycol monomethyl ether, propylene glycolmonomethyl ether; lactates such as ethyl lactate or methyl lactate, withethyl lactate being preferred; propionates, particularly methylpropionate and ethyl propionate; a Cellosolve ester such as methylCellosolve acetate; an aromatic hydrocarbon such toluene or xylene; or aketone such as methylethyl ketone, cyclohexanone and 2-heptanone.Typically the solids content of the photoresist varies between 5 and 35percent by weight of the total weight of the photoresist composition.

The photoresists of the invention can be used in accordance with knownprocedures. Though the photoresists of the invention may be applied as adry film, they are preferably applied on a substrate as a liquid coatingcomposition, dried by heating to remove solvent preferably until thecoating layer is tack free, exposed through a photomask to activatingradiation, optionally post-exposure baked to create or enhancesolubility differences between exposed and non-exposed regions of theresist coating layer, and then developed preferably with an aqueousalkaline developer to form a relief image. The substrate on which aresist of the invention is applied and processed suitably can be anysubstrate used in processes involving photoresists such as amicroelectronic wafer. For example, the substrate can be a silicon,silicon dioxide or aluminum-aluminum oxide microelectronic wafer.Gallium arsenide, ceramic, quartz or copper substrates may also beemployed. Substrates used for liquid crystal display and other flatpanel display applications are also suitably employed, e.g., glasssubstrates, indium tin oxide coated substrates and the like. A liquidcoating resist composition may be applied by any standard means such asspinning, dipping or roller coating. The exposure energy should besufficient to effectively activate the photoactive component of theradiation sensitive system to produce a patterned image in the resistcoating layer. Suitable exposure energies typically range from about 1to 300 mJ/cm². As discussed above, preferred exposure wavelengthsinclude sub-200 nm such as 193 nm. Suitable post-exposure baketemperatures are from about 50° C. or greater, more specifically fromabout 50 to 140° C. For an acid-hardening negative-acting resist, apost-development bake may be employed if desired at temperatures of fromabout 100 to 150° C. for several minutes or longer to further cure therelief image formed upon development. After development and anypost-development cure, the substrate surface bared by development maythen be selectively processed, for example chemically etching or platingsubstrate areas bared of photoresist in accordance with procedures knownin the art. Suitable etchants include a hydrofluoric acid etchingsolution and a plasma gas etch such as an oxygen plasma etch.

Composites

The invention provides a process for producing a composite comprising asubstrate and a coating that is applied onto the substrate in apatterned structure, the process comprising the steps of:

(a) applying a layer of the composition according to the invention ontothe surface of the substrate and at least partial removal of the organicsolvent (iii);

(b) exposing selected areas of the layer to electromagnetic radiation,thereby releasing an acid from the compound (i) in the areas exposed tothe electromagnetic radiation;

(c) optionally heating the layer to impart compound (ii) in the areas inwhich the acid has been released with an altered solubility in anaqueous solution; and

(d) at least partial removal of the layer.

In process step (a), a layer of the composition according to theinvention is applied onto the surface of the substrate followed by atleast partial removal of the organic solvent (iii).

Substrates may be any dimension and shape, and are preferably thoseuseful for photolithography, such as silicon, silicon dioxide,silicon-on-insulator (SOI), strained silicon, gallium arsenide, coatedsubstrates including those coated with silicon nitride, siliconoxynitride, titanium nitride, tantalum nitride, ultrathin gate oxidessuch as hafnium oxide, metal or metal coated substrates including thosecoated with titanium, tantalum, copper, aluminum, tungsten, alloysthereof, and combinations thereof. Preferably, the surfaces ofsubstrates herein include critical dimension layers to be patternedincluding, for example, one or more gate-level layers or other criticaldimension layer on the substrates for semiconductor manufacture. Suchsubstrates may preferably include silicon, SOI, strained silicon, andother such substrate materials, formed as circular wafers havingdimensions such as, for example, 20 cm, 30 cm, or larger in diameter, orother dimensions useful for wafer fabrication production.

Application of the composition according to the invention onto thesubstrate may be accomplished by any suitable method, including spincoating, spray coating, dip coating, doc-tor blading, or the like.Applying the layer of photoresist is preferably accomplished byspin-coating the photoresist using a coating track, in which thephotoresist is dispensed on a spinning wafer. During the spin coatingprocess, the wafer may be spun at a speed of up to 4,000 rpm, preferablyfrom about 500 to 3,000 rpm, and more preferably 1,000 to 2,500 rpm. Thecoated wafer is spun to remove the organic solvent (iii), and baked on ahot plate to remove residual solvent and free volume from the film tomake it uniformly dense.

In process step (b), selected areas of the layer are exposed toelectromagnetic radiation, there-by releasing an acid from the compound(i) in the areas exposed to the electromagnetic radiation. As statedabove, various exposure radiations can be used, including an exposurewith electromagnetic radiation having a wavelength of 365 nm (i-line),436 nm (g-line) or 405 nm (h-line), wherein electromagnetic radiationhaving a wavelength of 365 nm is particularly preferred.

Such a pattern-wise exposure can be carried out using an exposure toolsuch as a stepper, in which the film is irradiated through a patternmask and thereby is exposed pattern-wise. The method preferably usesadvanced exposure tools generating activating radiation at wavelengthscapable of high resolution including extreme-ultraviolet (EUV) or e-beamradiation. It will be appreciated that exposure using the activatingradiation decomposes the component according to the invention that iscontained in the photoresist layer in the exposed areas and generatesacid and decomposition by-products, and that the acid then effects achemical change in the polymer compound (ii) (de-blocking the acidsensitive group to generate a base-soluble group, or alternatively,catalyzing a cross-linking reaction in the exposed areas). Theresolution of such exposure tools may be less than 30 nm.

In process step (c), the layer can optionally be is heated to impartcompound (ii) in the areas in which the acid has been released with analtered solubility in an aqueous solution. In this so called“post-exposure bake” the solubility differences between exposed andunexposed regions of the coating layer are created or enhanced.Typically post-exposure bake conditions include temperatures of about50° C. or greater, more specifically a temperature in the range of fromabout 50° C. to about 160° C. for 10 seconds to 30 minutes, preferablyfor 30 to 200 seconds. According to a particular embodiment of theprocess according to the invention no heat treatment is performed afterprocess step (b) and before (d).

In process step (d) the layer is at least partially removed with anaqueous solution, preferably an aqueous base solution. This can beaccomplished by treating the exposed photoresist layer with a suitabledeveloper capable of selectively removing the exposed portions of thefilm (where the photoresist is positive tone) or removing the unexposedportions of the film (where the photoresist is negative tone).Preferably, the photoresist is positive tone based on a polymer havingacid sensitive (de-protectable) groups, and the developer is preferablya metal-ion free tetraalkylammonium hydroxide solution.

The composite made according to the invention is characterized in thatit comprises a substrate and a coating applied on the surface of thesubstrate in a patterned structure, wherein the coating comprises acompound according to the invention.

The use of the photoacid generator compounds of Formula (i) and (II) forphoto-induced polymerization, photo-induced cross-linking, photo-induceddegradation and photo-induced transformation of functional groups isalso within the scope of the invention. The compound according to theinvention is particularly suitable for use in protective coatings, smartcards, 3D rapid prototyping or additive manufacturing, sacrificialcoatings, adhesives, antireflective coatings, holograms, galvano- andplating masks, ion implantation masks, etch resists, chemical amplifiedresists, light sensing applications, PCB (printed circuit board)patterning, MEMS fabrication, TFT layer pattering on flat panel display,TFT layer pattering on flexible display, pixel pattering for display, incolor filters or black matrix for LCD, or semiconductor patterning inpackaging process and TSV related patterning on semiconductormanufacturing protective coatings, smart cards, 3D rapid prototyping oradditive manufacturing, sacrificial coatings, adhesives, antireflectivecoatings, holograms, galvano- and plating masks, ion implantation masks,etch resists, chemical amplified resists, light sensing applications orin color filters.

The following Examples are intended to illustrate the above inventionand should not be construed as to narrow its scope. One skilled in theart will readily recognize that the Examples suggest many other ways inwhich the invention could be practiced. It should be understood thatmany variations and modifications may be made while remaining within thescope of the invention.

EXAMPLES Solubility

Solubility is an important factor in the evaluation of a PAG. Highsolubility not only makes a PAG purified readily but also enables a PAGto be used for a wide range of concentrations in photoresists and invaried solvent systems. To test the solubility of a PAG, a solvent isslowly added until the PAG is completely dissolved and no turbidity isobserved in the clear solution. Table 8 lists the solubility (w/w %) ofsome representative N-hydroxynaphthalimide sulfonate derivatives versusNIT in various organic solvents at 20° C. All compounds of the inventionexhibit much higher solubility in PGMEA and cyclohexanone thancomparative compounds A and B and the commercial benchmark (NIT). Itshould be noted that compounds T2 and T5 exhibit extremely highsolubility in the tested solvents. These results indicate that theN-hydroxynaphthalimide sulfonate derivatives in the current inventionmay be used at high concentration in a photosensitive composition. Sincethe solubility of a PAG varies significantly with the change oftemperature, high solubility improves the solution stability of thephotosensitive composition so that the composition can be allowed for awide range of operating temperatures without worrying aboutrecrystallization of the PAG from the composition.

TABLE 8 Solubility (w/w %) Compound PGMEA* Cyclohexanone GBL**

1.7% 5.9% 2.2%

1.0% 3.5% 0.9%

6.1% 11.5% 2.3%

8.3% 19.7% 1.5%

45.8% 52.4% 23.1%

20.6% 42.0% 2.2%

50.1% 55.4% 32.4% *Propylene glycol monomethyl ether acetate**γ-ButyrolactonePhotoreactivity

A photoresist composition typically comprises PAG, polymers, additivesand solvents. The performance of a photoresist composition is mainlydependent on the properties of the PAG and polymer components. Toformulate a high-performance photoresist composition, morephotosensitive PAGs are typically selected. The photosensitivity of aPAG is typically directly related to the strength of the generated acidand the photoreactivity of the PAG. For a series of PAGs producing thesame latent acid, their photosensitivity is related only to theirphotoreactivity. Thus evaluating the photosensitivity of a PAG can beachieved by studying its photoreactivity. The higher photoreactivity,the higher photosensitivity. The photoreactivity can be investigated byphotolysis of a PAG in its dilute solution under low exposure intensity(to avoid side reactions which don't generate the desired acid). Thechange in the concentration of a PAG upon irradiation can be determinedby measuring the absorbance of the PAG at the maximum absorptionwavelength.

Photolysis of PAGs was carried out in acetonitrile in air at roomtemperature. The sodium salt of tetrabromophenol blue (TBPBNa), an acidindicator dye, which has a maximum absorption at 618 nm, was purchasedfrom Aldrich (indicator grade) and used as received. Irradiation of thesolution of the PAGs (3×10⁻⁵ M) was performed using a Cole-Parmer UV 15W bench lamp (EW-97605-50) at 365 nm. Light intensity was measured usingan UV Power Puck II radiometer from EIT Inc. UV-Vis spectra were run ona Thermo Scientific Evolution 201 UV-visible spectrophotometer.

Photolysis of NIT, comparative compound A and B, T1, T2, T3, and T5 wasexamined in acetonitrile. Referring to FIG. 1, the UV-Vis spectralchanges of T3 upon irradiation with a UV lamp at 365 nm, shows thedecrease of the intensity with the increase of exposure dose of energy(mJ/cm²). The absorption band at 362 nm (λ_(max)) gradually decreasesupon irradiation, indicating the progress of photoreaction with theincrease of exposure dose of energy. Assuming the photoreaction isfirst-order, a plot of the natural log of changes in absorbance withexposure dose of energy gives the photoreaction constant of T3 (i.e.,the slope of the linear trendline) (FIG. 2). The photoreaction constantsof other compounds were similarly determined under the same irradiationcondition. Comparing the constants of A, B, T1, T2, T3, and T5 with thatof NIT normalized to one gives the relative photoreactivity (Table 9).The photoreactivity for PAGs (T1, T2 and T3) according to this inventionis 8 to 10 times greater than that of NIT and 3 to 4 times greater thanthat of Comparative Compound A. The PAG (T1 and T3) with a nonaflategroup is more photoreactive than those with a triflate group. Theformation of acid upon irradiation was confirmed by observing thespectral changes of the acid indicator, TBPBNa at 618 nm.

TABLE 9 Comparison of solubility and photoreactivity. SolubilityRelative (w/w %) in Photoreactivity Solubility × PAG PGMEA* at 365 nmPhotoreactivity

1.7% 1.0  1.7% 

1.0% 2.5  2.5% 

6.1% 8.0 48.8% 

8.3% 9.3 77.2% 

45.8% 8.6 394%

20.6% 9.6 198%

50.1% 4.0 200% *= Propylene glycol monomethyl ether acetate **=N-Hydroxynaphthalimide triflate (NIT)Resist Evaluation

Referring to Table 10, four different photoresist compositions accordingto this invention were prepared by following this general procedure: 50g of PHS-EVE polymer solution (˜30 wt % polymer content in PGMEA; ca.35% of the OH groups blocked with EVE, Mw=32,000, Mw/Mn=1.88) and 50 gof PGMEA are pre-mixed. To this mixture are added 1.3 mmol of a PAG and0.0263 g (20 mol % of the PAG) of triethylamine was used as a quencher.The mixture was stirred until the solid was completely dissolved. Thecompositions were then stored in darkness for subsequent pattern studiesby photolithography.

TABLE 10 Composition Summary and Exposure Proper PAG exposure timeQuality Photoresist amount (normalized to of composition PAG (1.3 mmol)composition 1) pattern 1 NIT 0.449 g 1 + 2 T2 0.589 g 0.36 ++ 3 T350.574 g 0.74 ++ 4 T3 0.784 g 0.43 oPreparation of Patterned Structures

Compositions 1-4 were used to prepare patterned structures byphotolithography by following this general procedure. Each compositionwas coated on a bare glass wafer with sonication cleaning by a spincoater (1000 rpm, 40 s, ACE-200 model). The coating was soft-baked on ahot plate (LK LAB Korea, PDLP-250 Model with a SUS Cover) at 110° C. for60 s and subsequently exposed at i-line irradiation of ca. 100-280mJ/cm² with a photomask patterned with various line-and-space (L/S)sizes (5, 6, 7, 8, 9, and 10 μm) using a CoolUV-100 Mask Aligner withi-line (365 nm) LED light source which was manufactured from JaesungEngineering Co. (South Korea) at various exposure times. After 1-2minutes waiting time, the coating in the area exposed to radiation wasremoved to generate patterned structures by dipping the wafer into a2.38 wt % aqueous tetramethylammonium hydroxide (TMAH) solution for 1min at 23° C. Washing was performed by dipping in deionized water for 20seconds and dried by gently blowing with nitrogen.

The obtained patterned structures for compositions 1-4 (FIG. 3) werecarefully analyzed by a high-resolution microscope. Proper exposure timewas determined by stepwise changing the exposure time and checking thepattern after development and drying using a microscope (MU500 modelfrom AmScope Co., magnification: X500 and minimum 10 um in resolution).Proper exposure was reached, when the pattern showed the same size asthe mask. In case of over exposure the width of the space between thelines was wider, and in case of under exposure smaller than thecorresponding feature of the mask. Quality of the pattern was determinedby checking for lift-off or missing features after development anddrying. ++=no lift-off, no missing features, +=no lift off, some smallfeatures missing, o=lift-off or all small features missing. Thus,compounds according to the invention uniquely exhibit both highsolubility and high sensitivity (short exposure times).

UV-Vis Spectra

As shown in FIG. 4, the PAG compounds of this invention have excellentsolubility in organic solvents and strong absorption at i-line of amercury lamp. Compounds T1 and T2 exhibit an absorption maximum at 362nm, and compound T5 shows an absorption maximum at 353 nm. Theirabsorbance at i-line of a mercury lamp is much larger than that of NIT,for example, which is a prior art commercial PAG benchmark forperformance. Hence, compounds of the invention exhibit highersensitivity and better performance as PAGs in photolithography relativeto the prior art.

Preparation of PAG Compounds

Examples 2, 3, 4, 5, 6, 7, 8, and 9 describe examples of synthesis ofthe sulfonic acid derivatives according to this invention.

Example 1 Synthesis of Comparative Compound B

To a 5-L flask was charged 4-bromo-1,8-naphthalic anhydride (263 g,0.9492 mol), PPh₃ (19.92 g, 75.94 mmol), Et₃N (201.7 g, 1.99 mol) and 2L of THF. The mixture was stirred under nitrogen for 1 h. To thismixture was added CuI (5.42 g, 28.5 mmol) and Pd(PPh₃)₂Cl₂ (6.66 g,9.492 mmol) under nitrogen. The mixture was heated to reflux, and1-hexyne (101.8 g, 1.0 mol) in 0.5 L of THF was added dropwise in 2.5 h.After the addition, the mixture was kept at reflux for 14.5 h. TLCmonitoring of the reaction showed a small amount of the unreactedanhydride. An additional amount of 1-hexyne (14.5 g, 142 mmol) was addedin 0.5 h, and the mixture was kept at reflux for an additional 2 h. Themixture was allowed to slowly cool down to rt. 20 mL of DI water wasadded. Filtration gave a yellow solid, and the complete removal ofsolvents from the filtrate gave a dark brown solid. Both solids werecombined and then dissolved in 1 L of CH₂Cl₂. The solution was washedwith 1.5 L of DI water. Separation and rotavap of the CH₂Cl₂ solutiongave 208 g of the crude solid. Recrystallization from 320 mL of ACN gave200 g (yield: 70%) of B-I1 as light yellow crystals. Note that B-I1 wasused in the subsequent reaction without further purification. Mp: 153-4°C. ¹H NMR (300 MHz, CDCl₃) δ: 8.50 (d, 2H), 8.25 (d, 1H), 7.65 (t, 1H),7.58 (d, 1H), 2.53 (t, 2H), 1.62 (p, 2H), 1.45 (sextet, 2H), 0.91 (t,3H). ¹³C NMR (75.5 MHz, CDCl₃) δ: 13.6, 19.6, 22.2, 30.5, 103.5, 117.0,118.8, 127.5, 129.8, 130.2, 130.6, 131.7, 132.4, 133.4, 133.8, 160.0,160.4.

To a 1 L flask was charged B-I1 (100 g, 0.3593 mol), H2NOH.HCl (25.49 g,0.3593 mol), and pyridine (369.49 g, 4.671 mol). The mixture was heatedto reflux for 4 h. TLC monitoring the reaction showed the disappearanceof B-I1. The reaction mixture was cooled to −13° C. using an ice-saltbath. To this mixture was added dropwise triflic anhydride (222.85 g,0.7905 mol), and the temperature was kept below 10° C. during theaddition. The addition was completed in 4 h. 2 L of DI water was added,and the resulting mixture stirred at room temperature for 1 h.Filtration gave 139 g of the yellow solid. Recrystallization from 100 mLof ACN and 1.2 L of MeOH gave 115 g (yield: 75%) of compound B as lightyellow powder. Mp: 112-4° C. 1H NMR (300 MHz, CDCl3) δ: 8.60 (d, 1H),8.55 (d, 1H), 8.42 (d, 1H), 7.72 (m, 2H), 2.55 (t, 2H), 1.65 (p, 2H),1.45 (sextet, 2H), 0.95 (t, 3H). 13C NMR (75.5 MHz, CDCl3) δ: 13.6,19.7, 22.2, 30.5, 77.5, 103.6, 120.0, 121.7, 127.4, 127.6, 130.9, 131.0,132.1, 132.2, 133.1, 134.5, 158.7, 159.0.

Example 2 Synthesis of Compound T1

To a 1-L flask was charged B-I1 (54.3 g, 0.195 mol), 150 mL of DMF, andH₂NOH.HCl (13.84 g, 0.215 mol). To the slurry mixture was added dropwise48% KOH solution (12.04 g, 0.215 mol), and the temperature was keptunder 25° C. during the addition. After the addition, the reactionmixture was stirred at room temperature for 4 h. 500 mL of DI water wasadded. The mixture was stirred at room temperature for 2 h. Filtrationand washing with DI water gave a yellow solid. The solid was dried undervacuum at 60° C. overnight to give 57 g (yield: 99%) of the hydroxylimide B-I2. Note that B-I2 was used in the subsequent reaction withoutfurther purification. Mp: 163-6° C. ¹H NMR (300 MHz, DMSO) δ: 10.75 (s,1H), 8.42 (m, 2H), 8.32 (d, 1H), 7.82 (t, 1H), 7.70 (d, 1H), 2.58 (t,2H), 1.60 (p, 2H), 1.45 (sextet, 2H), 0.95 (t, 3H). ¹³C NMR (75.5 MHz,DMSO) δ: 13.4, 18.8, 21.5, 30.0, 77.4, 101.5, 121.4, 122.7, 126.0,127.5, 127.8, 130.0, 130.5, 130.97, 131.00, 131.8, 160.2, 160.5.

The nonaflate T1 was synthesized in 30% yield by the reaction of thehydroxyl imide B-I2 and C₄F₉SO₂F. Mp: 125-8° C. ¹H NMR (300 MHz, CDCl₃)δ: 8.55 (d, 1H), 8.50 (d, 1H), 8.45 (d, 1H), 7.73 (m, 2H), 2.55 (t, 2H),1.65 (p, 2H), 1.45 (sextet, 2H), 0.95 (t, 3H).

Example 3 Synthesis of Compound T2

The anhydride intermediate T2-I1 was similarly synthesized in 68% yieldby following the same procedure as B-I1 with 1-octyne replacing1-hexyne. Note that T2-I1 was used in the subsequent reaction withoutfurther purification. Mp: 100-1° C. ¹H NMR (300 MHz, CDCl₃) δ: 8.65 (d,1H), 8.60 (d, 1H), 8.45 (d, 1H), 7.78 (m, 2H), 2.54 (t, 2H), 1.66 (p,2H), 1.46 (p, 2H), 1.29 (m, 4H), 0.85 (t, 3H).

To a 1-L flask was charged T2-I1 (36 g, 0.1626 mol), 75 mL of DMF, andH₂NOH.HCl (13.58 g, 0.1952 mol). To the slurry mixture was addeddropwise 48% KOH solution (10.95 g, 0.1952 mol), and the temperature waskept under 25° C. during the addition. After the addition, the reactionmixture was stirred at room temperature for 4 h. 250 mL of DI water wasadded. The mixture was stirred at room temperature for 2 h. Filtrationand washing with DI water gave the yellow solid. The solid was driedunder vacuum at 60° C. overnight to give 35 g (yield: 93%) of thehydroxyl imide T2-I2. Note that T2-I2 was used in the subsequentreaction without further purification. Mp: 142-6° C. ¹H NMR (300 MHz,CDCl₃) δ: 8.80 (br s, 1H), 8.54 (m, 2H), 8.42 (d, 1H), 7.70 (m, 2H),2.54 (t, 2H), 1.67 (p, 2H), 1.48 (p, 2H), 1.29 (m, 4H), 0.85 (t, 3H).

To a 500 mL flask was charged T2-I2 (25 g, 77.8 mmol), acetonitrile (100mL) and pyridine (9.23 g, 116.7 mmol). The mixture was cooled to 0° C.,and triflic anhydride (27.4 g, 197.2 mmol) was then added dropwise below5° C. during the addition. After the addition, the reaction mixture wasallowed to warm to room temperature and stirred at room temperature for5 h. 300 mL of DI water was added to the mixture. Filtration gave ayellow solid. The solid was dissolved in 100 g of CH₂Cl₂, and thesolution was passed through a short pad of silica gel. Removal of CH₂Cl₂and recrystallization from a mixture of isopropanol (200 g) andacetonitrile (20 g) gave a yellow solid which was dried under vacuum at50° C. overnight to afford 15.9 g (yield: 45%) of T2. Mp: 66-8° C. ¹HNMR (300 MHz, CDCl₃) δ: 8.60 (m, 2H), 8.44 (d, 1H), 7.74 (t, 1H), 2.55(d, 2H), 1.67 (p, 2H), 1.48 (p, 2H), 1.28 (m, 4H), 0.83 (t, 3H). ¹³C NMR(75.5 MHz, CDCl₃) δ: 14.0, 20.0, 22.6, 28.4, 28.7, 31.3, 77.5, 103.7,120.0, 121.7, 127.3, 127.5, 130.8, 130.9, 132.1, 132.2, 133.1, 134.5,158.7, 159.0.

Example 4 Synthesis of Compound T3

The nonaflate T3 was synthesized in 42% yield by the reaction of thehydroxyl imide T2-I2 and C₄F₉SO₂F. Mp: 115-6° C. ¹H NMR (300 MHz, CDCl₃)δ: 8.60 (m, 2H), 8.42 (d, 1H), 7.74 (m, 2H), 2.52 (t, 2H), 1.65 (p, 2H),1.45 (m, 2H), 1.28 (m, 2H), 0.95 (t, 3H). ¹³C NMR (75.5 MHz, CDCl₃) δ:14.0, 20.0, 22.5, 28.4, 28.7, 31.3, 77.5, 103.6, 120.0, 121.7, 127.3,127.5, 130.8, 130.9, 132.0, 132.2, 133.1, 134.4, 158.7, 158.9.

Example 5 Synthesis of Compound T5

The anhydride intermediate T5-I1 was similarly synthesized in 28% yieldby following the same procedure as B-I1 with propargyl butyrate (easilyprepared by the reaction of propargyl alcohol with butyryl chloride inthe presence of triethylamine) replacing 1-hexyne. Note that T5-I1 wasused in the subsequent reaction without further purification. Mp: 135-7°C. ¹H NMR (300 MHz, CDCl₃) δ: 8.63 (m, 2H), 8.49 (d, 1H), 7.84 (m, 2H),5.02 (s, 2H), 2.36 (t, 2H), 1.67 (sextet, 2H), 0.94 (t, 3H).

To a flask was charged T5-I1 (4.9 g, 15.2 mmol), 10 mL of DMF, andH₂NOH.HCl (1.078 g, 16.72 mmol). To the slurry mixture was addeddropwise 48% KOH solution (0.938 g, 16.72 mmol), and the temperature waskept under 25° C. during the addition. After the addition, the reactionmixture was stirred at room temperature overnight. 30 mL of DI water wasadded, and the mixture was stirred at room temperature for 1 h.Filtration and washing with DI water gave the yellow solid. The solidwas recrystallized from a mixture of CH₂Cl₂ and EA to afford 3.5 g(yield: 68%) of the hydroxyl imide, T5-I2. Mp: 180-2° C. ¹H NMR (300MHz, CDCl₃) δ: 8.60 (m, 2H), 8.50 (d, 1H), 7.82 (m, 2H), 5.02 (s, 2H),2.36 (t, 2H), 1.67 (sextet, 2H), 0.94 (t, 3H).

To a flask was charged T5-I2 (3.0 g, 8.89 mmol), acetonitrile (15 mL)and pyridine (1.06 g, 13.34 mmol). The mixture was cooled to 0° C., andtriflic anhydride (3.13 g, 11.11 mmol) was then added dropwise below 5°C. during the addition. After the addition, the reaction mixture wasallowed to warm to room temperature and stirred for 2 h. 100 mL of DIwater was added to the mixture. Filtration gave the yellow solid. Thesolid was dissolved in 10 g of CH₂Cl₂, and the solution was passedthrough a short pad of silica gel. Removal of CH₂Cl₂ andrecrystallization from a mixture of isopropanol (20 g) and DI water (2g) gave a yellow solid which was dried under vacuum at 50° C. overnightto afford 3.2 g (yield: 76%) of T5. Mp: 87-9° C. ¹H NMR (300 MHz, CDCl₃)δ: 8.61 (m, 2H), 8.50 (d, 1H), 7.83 (m, 2H), 5.01 (s, 2H), 2.36 (t, 2H),1.67 (sextet, 2H), 0.93 (t, 3H). ¹³C NMR (75.5 MHz, CDCl₃) δ: 13.6,18.4, 35.9, 52.2, 82.3, 94.7, 120.8, 121.3, 121.8, 127.2, 128.1, 131.5,131.8, 132.1, 133.3, 134.2, 158.5, 158.8, 172.9.

Example 6 Synthesis of Compound T35

The anhydride intermediate T35-I1 was similarly synthesized in 64% yieldby following the same procedure as B-I1 with propargyl butyrate (easilyprepared by the reaction of propargyl alcohol with acetyl chloride inthe presence of triethylamine) replacing 1-hexyne. Note that T35-I1 wasused in the subsequent reaction without further purification. Mp: 173-6°C. ¹H NMR (300 MHz, CDCl₃) δ: 8.60 (m, 2H), 8.46 (d, 1H), 7.82 (m, 2H),5.01 (s, 2H), 2.13 (s, 3H).

To a flask was charged T35-I1 (10 g, 34.0 mmol), 15 mL of DMF, andH₂NOH.HCl (2.60 g, 37.4 mmol). To the slurry mixture was added dropwise48% KOH solution (2.10 g, 37.4 mmol), and the temperature was kept under25° C. during the addition. After the addition, the reaction mixture wasstirred at room temperature overnight. 30 mL of DI water was added. Themixture was stirred at room temperature for 1 h. Filtration and washingwith DI water gave the solid which was dried under vacuum at 60° C. toafford 9.0 g (yield: 86%) of the hydroxyl imide, T35-I2. Note thatT35-I1 was used in the subsequent reaction without further purification.

To a flask was charged T35-I2 (8.7 g, 28.1 mmol), acetonitrile (50 mL)and pyridine (3.33 g, 42.1 mmol). The mixture was cooled to 0° C., andtriflic anhydride (9.9 g, 35.1 mmol) was then added dropwise below 5° C.during the addition. After the addition, the reaction mixture wasallowed to warm to room temperature and stirred at room temperature for2 h. 100 mL of DI water was added to the mixture. Filtration gave theyellow solid. The solid was dissolved in 10 g of CH₂Cl₂, and thesolution was passed through a short pad of silica gel. Removal of CH₂Cl₂and recrystallization from a mixture of isopropanol (50 mL) and ACN (25mL) gave a yellow solid which was dried under vacuum at 50° C. overnightto afford 8 g (yield: 64%) of T35. Mp: 157-9° C. ¹H NMR (300 MHz, CDCl₃)δ: 8.61 (m, 2H), 8.50 (d, 1H), 7.83 (m, 2H), 5.01 (s, 2H), 2.13 (s, 3H).¹³C NMR (75.5 MHz, CDCl₃) δ: 20.7, 52.4, 82.4, 94.4, 121.4, 121.8,127.3, 128.1, 128.5, 131.6, 131.8, 132.1, 133.4, 134.2, 158.5, 158.8,172.9.

Example 7 Synthesis of Compound T38

To a 1-L flask was charged B-I2 (15 g, 51.1 mmol), 60 mL of ACN, andEt₃N (5.7 g, 56.2 mmol). The mixture was cooled to 0° C., and CH₃SO₂Cl(6.44 g, 56.2 mmol) was added dropwise. After the addition, the reactionmixture was allowed to warm to room temperature and stirred at roomtemperature for 3 h. 200 mL of DI water was added, and the mixture wasstirred at room temperature for 1 h. Filtration and washing with DIwater gave 18.6 of the yellow solid. The solid was recrystallized fromEA to give 16.7 g (yield: 88%) of T38. Mp: 121-2° C. ¹H NMR (300 MHz,CDCl₃) δ: 8.60 (m, 2H), 8.45 (d, 1H), 7.72 (m, 2H), 3.52 (s, 3H), 2.55(t, 2H), 1.62 (p, 2H), 1.50 (m, 2H), 0.95 (t, 3H).

Example 8 Synthesis of Compound T40

To a 1-L flask was charged B-I2 (20 g, 68.2 mmol), 80 mL of ACN, andEt₃N (7.6 g, 75 mmol). The mixture was cooled to 0° C., and BuSO₂Cl(11.74 g, 75 mmol) was added dropwise. After the addition, the reactionmixture was allowed to warm to room temperature and stirred at roomtemperature for 3 h. 200 mL of DI water was added, and the mixture wasstirred at room temperature for 1 h. Filtration and washing with DIwater gave the yellow solid. The solid was recrystallized from ACN togive 25.6 g (yield: 91%) of T40. Mp: 110-1° C. ¹H NMR (300 MHz, CDCl₃)δ: 8.45 (m, 2H), 8.35 (d, 1H), 7.62 (m, 2H), 3.62 (t, 2H), 2.52 (t, 2H),2.02 (m, 2H), 1.62 (m, 2H), 1.45 (m, 4H), 0.95 (m, 6H).

Example 9 Synthesis of Compound T39

To a 1-L flask was charged B-I2 (15 g, 51.1 mmol), 80 mL of ACN, andEt₃N (5.7 g, 56.2 mmol). The mixture was cooled to 0° C., andcamphorsulfonyl chloride (14.1 g, 56.2 mmol) was added dropwise. Afterthe addition, the reaction mixture was allowed to warm to roomtemperature and stirred at room temperature for 3 h. 200 mL of DI waterwas added, and the mixture was stirred at room temperature for 1 h.Filtration and washing with DI water gave the yellow solid. The solidwas recrystallized from EA to give 18 g (yield: 70%) of T39. Mp: 124-6°C. ¹H NMR (300 MHz, CDCl₃) δ: 8.60 (m, 2H), 8.50 (d, 1H), 7.65 (m, 2H),4.15 (d, 1H), 3.85 (d, 1H), 2.55 (t, 2H), 2.40 (m, 2H), 1.30-2.10 (br m,9H), 1.12 (s, 3H), 0.95 (m, 6H).

Example 10 Synthesis of Comparative Compound A

The anhydride intermediate A-I1 was similarly synthesized in 75% yieldby following the same procedure as B-I1 with phenylacetylene replacing1-hexyne. Note that A-I1 was used in the subsequent reaction withoutfurther purification.

To a 1-L flask was charged A-I1 (81 g, 271.5 mmol), 250 mL of DMF, andH₂NOH.HCl (18.4 g, 285.1 mmol). To the slurry mixture was added dropwise48% KOH solution (16.0 g, 285.1 mmol), and the temperature was keptunder 25° C. during the addition. After the addition, the reactionmixture was stirred at room temperature for 4 h. 250 mL of DI water wasadded. The mixture was stirred at room temperature for 2 h. Filtrationand washing with DI water gave the yellow solid. The solid was driedunder vacuum at 60° C. overnight to give 80 g (yield: 94%) of thehydroxyl imide A-I2. Note that A-I2 was used in the subsequent reactionwithout further purification. Mp: 194-9° C.

To a 500 mL flask was charged A-I2 (55 g, 175.5 mmol), acetonitrile (200mL) and pyridine (23.6 g, 298.4 mmol). The mixture was cooled to 0° C.,and triflic anhydride (74.3 g, 263.3 mmol) was then added dropwise below5° C. during the addition. After the addition, the reaction mixture wasallowed to warm to room temperature and stirred at room temperatureovernight. The mixture was heated to reflux for 30 min and cooled downto rt. 200 mL of DI water was added to the mixture and stirred at roomtemperature for 10 min. Filtration gave the yellow solid which wasdissolved in 1 L of CH₂Cl₂, and the solution was passed through a shortpad of silica gel. The solution was subject to rotavap until 100 g ofCH₂Cl₂ was left. Filtration gave a yellow solid which was dried undervacuum at 50° C. overnight to afford 46 g (yield: 59%) of A. Mp: 193-5°C. ¹H NMR (300 MHz, DMSO) δ: 8.94 (d, 1H), 8.70 (d, 1H), 8.63 (d, 1H),8.18 (d, 1H), 8.10 (dd, 1H) 7.82 (m, 2H), 7.52 (m, 3H).

Although illustrated and described above with reference to certainspecific embodiments and examples, the invention is nevertheless notintended to be limited to the details shown. Rather, variousmodifications may be made in the details within the scope and range ofequivalents of the claims and without departing from the spirit of theinvention. It is expressly intended, for example, that all rangesbroadly recited in this document include within their scope all narrowerranges which fall within the broader ranges. In addition, features ofone embodiment may be incorporated into another embodiment.

What is claimed is:
 1. A sulfonic acid derivative compound representedby either Formula (I) or Formula (II):

wherein R⁰ is an aliphatic group having a carbon number of from 2 to 18which comprises at least one —C(═O)—O— moiety, and wherein the aliphaticgroup optionally comprises at least one halogen atom; and R is analiphatic group having a carbon number of from 2 to 18, which may besubstituted by one or more halogen atom(s).
 2. The sulfonic acidderivative compound of claim 1 selected from the group consisting of

and


3. A sulfonic acid derivative compound represented by either Formula (I)or Formula (II):

wherein

R⁰ is an aliphatic group having a carbon number of from 2 to 18 whichcomprises at least one moiety selected from the group consisting of —O—,—S—, —C(═O)—, —C(═O)—O—, or —O—C(═O)—O—, wherein the aliphatic groupoptionally comprises at least one halogen atom; and R is —CF₃.
 4. Thesulfonic acid derivative compound of claim 3 wherein R is —CF₃ and R⁰ isan aliphatic group having a carbon number of from 2 to 18 whichcomprises at least one —O—, —S—, —C(═O)—, —C(═O)—O—, or —O—C(═O)—O—moiety, wherein the aliphatic group optionally comprises at least onehalogen atom.
 5. The sulfonic acid derivative compound of claim 4selected from the group consisting of


6. The sulfonic acid derivative compound of claim 5 represented by theformula


7. The sulfonic acid derivative compound of claim 4 selected from thegroup consisting of


8. A photoresist composition comprising: (i) at least one sulfonic acidderivative compound according to claim 3; (ii) at least one polymer orcopolymer which is capable of being imparted with an altered solubilityin an aqueous solution in the presence of an acid; (iii) an organicsolvent; and, optionally, (iv) an additive.
 9. The composition accordingto claim 8, wherein the at least one organic solvent (iii) is selectedfrom the group consisting of a ketone, an ether, and an ester.
 10. Thecomposition according to claim 8 comprising: 0.05 to 15 wt. % of the atleast one sulfonic acid derivative compound; 5 to 50 wt. % of the atleast one polymer or copolymer; 0 to 10 wt. % of the additive; andreminder organic solvent.
 11. A process of producing a patternedstructure on the surface of a substrate, the process comprising thesteps of (a) applying a layer of the composition according to claim 8onto the surface of the substrate and at least partial removal of theorganic solvent (iv); (b) exposing the layer to electromagneticradiation, thereby releasing an acid from the sulfonic acid derivativecompound (i) in the areas exposed to the electromagnetic radiation; (c)optionally heating the layer to impart compound (ii) in the areas inwhich the acid has been released with an increased solubility in anaqueous solution; and (d) at least partial removal of the layer with anaqueous solution in these areas.
 12. A sulfonic acid derivative compoundrepresented by either Formula (I) or Formula (II):

wherein R⁰ is an aliphatic group having a carbon number of from 2 to 18which comprises at least one —C(═O)—S—, —C(═O)—NH—, —O—C(═O)—NH—,—C(═O)—NR_(a)—, —O—C(═O)—NR_(a), or —C(═O)—NR_(a)R_(b) moiety, whereinR_(a) and R_(b) are as defined above, and wherein the aliphatic groupoptionally comprises at least one halogen atom; and R is —CF₃.
 13. Thesulfonic acid derivative compound of claim 12 selected from the groupconsisting of